A common application of piezo-electric actuators is for controlling fluid flow through a valve. Piezo-electric actuators such as benders are typically made from layers of piezoceramic material (such as lead zirconate titanate, for example) stacked between conducting electrodes, typically metal, across which electric potentials are applied for creating electric fields across the piezoceramic layers.
Piezo-electric benders, when used to control fluid flow, are typically isolated from the fluid to prevent corrosion and chemical attack by the fluid on the metal and piezoceramic layers. One failure mode of piezo-electric benders immersed in water is the growth of metallic dendrites through the ceramic layers with subsequent shorting together of the conducting layers. Even if the bender is coated, water may interact corrosively with the coating and cause its breakdown.
Accordingly, it is desirable to develop a configuration permitting a piezo-electric actuator to work immersed in water or other electrolytic fluid.